I decided over christmas to try to build a PVR box.
I ordered a MSI barebones box with the usual extras.
There is several very good PVR software packages like Mediaportal for Windows and MythTV for Linux, but I’m going to use Freevo as it is written in Python, yummy 
Build your own PVR seems to be a good website for PVR builders.
I’ll let you know how I get on.
BTW, anybody know about the internals of the NTL digital decoder box?